This application claims benefit of Japanese Patent Application Nos. 2004-004301, 2004-013995 and 2004-027685 filed on Jan. 9, 2004, Jan. 22, 2004 and Feb. 4, 2004, respectively, the contents of which are incorporated by the reference.
The present invention relates to disk drive devices, disk drive systems and disks capable of signal transmission and/or receipt between disk and disk drive device with a simple arrangement.
Optical disks, although made of very inexpensive materials such as polycarbonate or like resins, are capable of recording very great amounts of data quantities and also very advantageous in view of the cost performance. Thus, the optical disks are most promising as future recording medium.
For reading out and writing data from and in an optical disk (data read/write), a disk drive device is used. The disk drive device is arranged such that an optical disk is set on a turntable, clamped by a clamp and driven for rotation by a spindle motor that the disk in this state is irradiated by a laser beam, and that a reflected beam from the disk surface is received and demodulated, thereby reading out the recorded data. Typical examples of such disk drive device arrangement are disclosed in Literatures 1 to 3 (see Japanese Patent-Laid Open Heisei 11-353749, Japanese Patent-Laid Open 2000-100031 and Japanese Patent-Laid Open 2000-100032).
Recently, such optical disks have been proposed that not only a recording area but also an electronic circuit or like electric circuit is formed thereon. However, due to the fact that the optical disk and the disk dive device are operable in a state of being perfectly electrically insulated from each other and also that the optical disk is driven for rotation at a high speed it is not so easy to carry out signal transmission and/or receipt between the electronic circuit formed on the optical disk and an internal circuit formed on the side of the disk drive device.
What utilizes radio signal as signal transmitted and received between the disk side and disk drive side, has been proposed as disk drive device of the pertaining type for driving the optical disk. As an example, the optical disk surface and the disk drive surface are each formed with an antenna for radio signal transmission and/or receipt via these antennas.
It has also been conceived to form each of the optical drive side and the disk drive with a light emitting/receiving circuit for optical signal transmission and/or receipt via these light emitting/receiving circuits.
In a further proposed arrangement, signal transmission and/or receipt between the electronic circuit and the disk drive side is carried out in a state that the disk drive is held stationary (see Literature 4: U.S. Pat. No. 5,119,353).
As shown above, in the prior art the transmission and/or receipt of signals between the electronic circuit formed on the disk surface and the internal circuit in the disk drive device, is carried out as the radio signal transmission and/or receipt via the antennas formed on the disk surface and the disk drive side, respectively. However, such antennas should be formed with shape parameters fitted for the radio signal frequency, and also the formation of the antenna on the disk surface requires a highly accurate etching (forming) technique. Furthermore, it is necessary to form a frequency converter circuit for frequency conversion to and from the radio frequency. These facts are significant problems for the optical disk, the low cost of which is greatly beneficial. Furthermore, the radio frequency transmission and/or receipt characteristic is easily influenced or deteriorated by metal materials close to the transmission/reception means such as the reflected metal layer in the disk.
In the case of the arrangement adapted for optical signal transmission and/or receipt via the light emitting/receiving circuits formed on the optical disk side and the disk drive device side, respectively, it is necessary to form an optical/electric signal converter circuit on each disk, which is a significant problem likewise for the optical disk featuring utmost preference in cost.
In the case of carrying out the signal transmission and/or receipt between the electronic circuit and the internal circuit on the disk drive device side in the state that the disk drive device is held stationary, the signal transmission and/or receipt between the disk circuit and the disk drive device side can not be obtained while the disk is driven for rotation, and real-time signal processing is impossible.
In the meantime, it is presumed to form not only a single but plurality of electronic circuits on the disk. In the prior art, it is impossible to cope with transmission and/or receipt of signals with respect to the disk drive device under such presumption. Foe example, it is very difficult to supply the electric power to the electric circuit on the disk.